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91 lines
2.2 KiB
C
91 lines
2.2 KiB
C
/*-------------------------------------------------------------------------
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*
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* pqsignal.c
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* reliable BSD-style signal(2) routine stolen from RWW who stole it
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* from Stevens...
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*
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* Portions Copyright (c) 1996-2018, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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*
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* IDENTIFICATION
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* src/port/pqsignal.c
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*
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* We now assume that all Unix-oid systems have POSIX sigaction(2)
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* with support for restartable signals (SA_RESTART). We used to also
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* support BSD-style signal(2), but there really shouldn't be anything
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* out there anymore that doesn't have the POSIX API.
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*
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* Windows, of course, is resolutely in a class by itself. In the backend,
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* we don't use this file at all; src/backend/port/win32/signal.c provides
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* pqsignal() for the backend environment. Frontend programs can use
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* this version of pqsignal() if they wish, but beware that this does
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* not provide restartable signals on Windows.
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*
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* ------------------------------------------------------------------------
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*/
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#include "c.h"
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#include <signal.h>
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#if !defined(WIN32) || defined(FRONTEND)
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/*
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* Set up a signal handler, with SA_RESTART, for signal "signo"
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*
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* Returns the previous handler.
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*/
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pqsigfunc
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pqsignal(int signo, pqsigfunc func)
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{
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#ifndef WIN32
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struct sigaction act,
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oact;
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act.sa_handler = func;
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sigemptyset(&act.sa_mask);
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act.sa_flags = SA_RESTART;
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#ifdef SA_NOCLDSTOP
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if (signo == SIGCHLD)
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act.sa_flags |= SA_NOCLDSTOP;
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#endif
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if (sigaction(signo, &act, &oact) < 0)
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return SIG_ERR;
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return oact.sa_handler;
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#else /* WIN32 */
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return signal(signo, func);
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#endif
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}
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/*
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* Set up a signal handler, without SA_RESTART, for signal "signo"
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*
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* Returns the previous handler.
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*
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* On Windows, this would be identical to pqsignal(), so don't bother.
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*/
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#ifndef WIN32
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pqsigfunc
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pqsignal_no_restart(int signo, pqsigfunc func)
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{
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struct sigaction act,
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oact;
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act.sa_handler = func;
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sigemptyset(&act.sa_mask);
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act.sa_flags = 0;
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#ifdef SA_NOCLDSTOP
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if (signo == SIGCHLD)
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act.sa_flags |= SA_NOCLDSTOP;
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#endif
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if (sigaction(signo, &act, &oact) < 0)
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return SIG_ERR;
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return oact.sa_handler;
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}
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#endif /* !WIN32 */
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#endif /* !defined(WIN32) || defined(FRONTEND) */
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